Many leading figures in the American left harbor intense animosity toward the Jewish people and the state of Israel.

The Center for Constitutional Rights (CCR), for example, honors the memory of activist Rachel Corrie, the International Solidarity Movement volunteer who was accidentally killed while trying to obstruct the path of a bulldozer that was engaged in anti-terror operations by Israeli Defense Force (IDF) soldiers in Gaza. CCR filed a federal lawsuit against Caterpillar Inc., the Illinois-based manufacturer of that and other IDF bulldozers.

Major anti-war groups such as Global Exchange, United For Peace and Justice, and Code Pink for Peace have campaigned against American aid to Israel, and have denounced Israel's construction of an anti-terrorist security fence in the West Bank -- dubbing it an "apartheid wall" that violates the civil and human rights of Palestinians.

The Green Party of the United States characterizes Israel as “comparable” -- in its alleged violation of Palestinian human rights -- to the former apartheid state of South Africa. In an effort to punish Israel, the Green Party has called for an international boycott of that country. The Green Party also supports the Palestinians' so-called "right of return" to land from which they were allegedly dispossessed in Israel, a policy which if ever implemented would create an influx of more than 5 million Arabs into Israel and would render the nation's Jews, virtually overnight, a permanent minority in their own state.

In a 2005 report the U.S. Civil Rights Commission considered the America left’s animus toward Israel and the Jews:

“The assault on Jewish nationalism is embedded in the ideology of the left.... As mystifying as it may be, the left sees no contradiction between its espousal of racial and ethnic equality and its prejudice against Jewish national identity.... This hatred of Israel does not exclusively stem from anti-Semitism, but also includes the demonization of America and the West as well. In this way, anti-Israelism from the left can be closely related to anti-Americanism. Over time, coming full circle, anti-Americanism endorses and devolves into anti-Semitism. And in cases where America is framed as a proxy for Israel and Jews, anti-Americanism and anti-Semitism become one in the same.”

In a similar vein, former Israeli politician Natan Sharansky writes:

“Anti-Semitism, which in the past had been the province of the radical right, is gaining more and more ground among organizations and societies which had, in the past, symbolized the forces of enlightenment, progress and democracy: the left wing political parties, human rights organizations, academic communities and anti-globalization movements. Those that had been the leaders of the struggle against racism in its various forms now lead the boycotting of Israel, its ostracism from the family of nations and accusations against crimes of humanity. The absurdity shouts to the skies.”

Conservative author and columnist Don Feder has identified several major causes of leftist anti-Semitism:

Jew-hatred has deep historic roots in the hardcore left. Karl Marx, who came from a Jewish family that converted to Christianity, was a rabid anti-Semite.

The left hates capitalism, which it identifies with Jews going back at least to the Rothschilds, a wealthy European dynasty of German Jewish origin. This animus is heightened by Jewish success in business and the professions.

The left is prone to accept conspiracy theories contending that dark and sinister forces secretly manipulate world events. The longest-running conspiracy theory of all, which it once scorned, it now accepts: the International Jewish Conspiracy, which holds that “the Jews” are the invisible force behind wars, depressions, economic downturns, and other problems from which an elite can profit.

Neo-Marxists believe that because Jews support Israel, there must be something inherently wrong with members of the tribe. The left’s anti-Israel obsession easily morphs easily to a view that is anti-Jew.